The development of navigation solutions in the absence of Global Positioning System (GPS) signals is receiving much attention from both commercial and military organizations. A navigation system that provides accurate information in the absence of a GPS signal is useful in first responder applications, as well as military operations in urban areas.
Inertial navigation systems are used in civil and military applications, in both manned and unmanned vehicles. A typical Inertial Navigation System (INS) includes an Inertial Measurement Unit (IMU) combined with processing to determine the navigation state of the system, which may include position, velocity, and attitude. An IMU includes inertial sensors or instruments such as accelerometers and/or gyroscopes for detecting and measuring inertial motion and acceleration in multiple directions.
Conventional navigation systems use indigenous sensors to determine the best estimate of a navigation solution. In certain environments, such navigation systems degrade in performance due to unavailability of a class of measurements. By communicating with other navigation systems in the vicinity, it is possible to recapture acceptable performance and sometimes improve indigenous sensor aided performance.